Challenges in Addressing Sentinel Setbacks for US Nukes

The LGM-35A Sentinel intercontinental ballistic missile (ICBM) program, developed by the US Air Force and Northrop Grumman, The project is projected to cost 37% more than initially budgeted and take at least two years longer to reach its initial operational capability than previously anticipated.

The delay will require the US Air Force to extend the life of some of its Minuteman ICBMs, which comprise one of the three major components of the US nuclear triad. The replacement of the ground-based US nuclear arsenal anchored by the Minuteman III has officially exceeded its $95.8 billion budget due to the Covid-19 pandemic and inflation. The cost overrun owes to the modernization of 450 missile silos and their command infrastructure, including 12,070 kilometers of new cables.

The US Defense Department must proceed with the LGM-35A Sentinel program, potentially costing over $125 billion, to replace LGM-30G Minuteman IIIs by 2029 and continue until the 2070s. Delays in LGM-35A Sentinel production could mean the US has to rely on increasingly obsolete nuclear weapons for strategic deterrence, in contrast to its near-peer adversaries China and Russia.

The US may be facing greater challenges in producing nuclear warheads than upgrading its delivery systems, according to a Heritage Foundation report. The authors argue that the US cannot use plutonium from decommissioned warheads in new ones, as microscopic changes can affect the storage safety and explosive yield of nuclear weapons. Existing US plutonium nuclear pits, designed for older weapons, may not give the desired results when used in newer weapons.

The US must produce 80 plutonium pits by 2026 to modernize its nuclear arsenal, but current production capacity means it won’t have 80 pits annually until 2030 or possibly until 2040. The shortfall is attributed to a culture of complacency, a lack of skilled nuclear expert workers, flagging industrial infrastructure, and restrictive environmental regulations surrounding plutonium processing.

The US National Nuclear Security Administration plans to build 50 new pits yearly at the Savannah River Site in South Carolina and 30 at Los Alamos National Laboratory in New Mexico, with the first pits for a new warhead, the W87-1, which would arm the LGM-35A Sentinel.

In 2007, JASON, a group of scientists, advised the US government that US plutonium pits would last decades longer, implying no new need to manufacture new pits. However, in 2019, JASON reversed its position, urging the US government to restart the production of plutonium pits.

The US National Nuclear Security Administration’s studies predicted that plutonium pits could last 150 years, but their degradation could result in surprise defects. Restarting US pit production is challenging, with Los Alamos’ efforts a year behind schedule and Savannah River’s five years behind schedule. In contrast, China is moving ahead with fissile material production, enlarging and modernizing its nuclear arsenal.

A Federation of American Scientists report suggests that China will likely source significant stocks of weapons-grade plutonium from civilian reactors, including two CFR-600 fast breeder reactors under construction at Xiapu in Fujian province. Once both reactors are operational, they could enable China to produce 330 kilograms of plutonium annually, consistent with US estimates that China will have more than 1,000 additional nuclear warheads by 2035.

Challenges in Addressing Sentinel Setbacks for US NukesLGM-35A Sentinel intercontinental ballistic missile (ICBM) programLGM-35A Sentinel programNorthrop GrummanUnited StatesUS Air ForceUS Defense Department must proceedUS National Nuclear Security AdministrationUS Nukes